Iron is a nagging problem for many Americans. Largely resigned to well water, iron causes red staining of tubs, sinks and fixtures, it fouls and ruins hot water tanks, stains clothing, leaves spots on dishes, windows, and vehicles, and makes water smell and taste bad. Anyone who has iron in their drinking water does not have to be told or see a test for it. The telltale signs are universally infamous.

Iron exists in two chemical states; The ferrous form is clear and dissolved in water. The other form, ferric iron is the oxidized form that we commonly refer to as rust.

The overwhelming majority of iron-removal technologies involve treating the ferrous form with an oxidizing agent that will convert (oxidize) the contaminant to ferric rust, then removing it/screening it/filtering it out using gravity and some form of cartridge technology.

Ferrous iron can be oxidized in a variety of ways. Chosen methods are often defined by economics, product availability and existing filtration technology.

  • Simply stirring/sloshing/aerating iron-contaminated water, will eventually cause the iron to precipitate out, i.e. form rust
  • Adding 2 – 5 mg/l of chlorine (bleach) to the above method will enhance the oxidation process.
  • A back-washable filter containing manganese greensand media, regenerated with potassium permanganate has been a staple filter for oxidizing iron for many years, and is still widely used today. This technology is somewhat messy and can leave pink/purple stains around the water system, as-well-as a pink tint in the resulting water. It is however, 90-100% effective at iron reduction.
  • A back-washable filter containing one of the newer oxidation media such as KDF® can be charged with chlorine, provide excellent iron reduction an overall operation that is neater than a permanganate system.

 KEY WATER DROPLET– Water Softeners are effective at removing small amounts of iron but are increasingly subject to iron fouling and contamination with iron-feeding bacteria as the iron concentration increases. As a rule, once the iron content reaches or exceeds 0.3 mg/l or .3 ppm, an alternative technology is preferable.

 KEY WATER DROPLET BONUS – Rotten egg small in water, caused by hydrogen sulfide can also be reduced and/or eliminated with an oxidation system. Chlorination is especially effective as is some forms of ultraviolet light treatment.